President Obama has authorized airstrikes against the Islamic State group in Northern Iraq to protect U.S. personnel there and to save Yazidis, an ethnic and religious minority who are threatened with genocide. The majority of the American public supports the airstrikes, but many are asking: why does the U.S. intervene militarily in some conflicts but not others? And why Iraq specifically?

The U.S. has launched airstrikes in Iraq in part because of a humanitarian crisis involving Yazidis, an ethnic and religious minority group in the country. ISIS — the Islamic State of Iraq and al-Sham- has targeted Yazidis, so who are they? AJ+ gives you a quick primer.